LED array with light intensity adaptive LED sidewalls

ABSTRACT

A first LED with a first LED sidewall is disclosed. A second LED with a second LED sidewall facing the first LED sidewall is also disclosed. A first dynamic optical isolation material between the first LED sidewall and the second LED sidewall and configured to change an optical state based on a state trigger such that a light behavior at the first LED sidewall for a light emitted by one of the first LED and the second LED is determined by the optical state, is also disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/912,496, filed Jun. 25, 2020, which is a continuation of U.S. patentapplication Ser. No. 16/226,487, filed Dec. 19, 2018, which claimsbenefit of priority to U.S. Provisional Application No. 62/609,202 filedDec. 21, 2017, to European Patent Application No. 18162551.8 filed Mar.19, 2018, and to European Patent Application No. 18191100.9 filed Aug.28, 2018. Each of the above patent applications is incorporated hereinby reference in its entirety.

BACKGROUND

Precision control lighting applications can require production andmanufacturing of small addressable light emitting diode (LED) pixelsystems. Manufacturing such LED pixel systems can require accuratedeposition of material due to the small size of the pixels and the smalllane space between the systems.

Semiconductor light-emitting devices including LEDs, resonant cavitylight emitting diodes (RCLEDs), vertical cavity laser diodes (VCSELs),and edge emitting lasers are among the most efficient light sourcescurrently available. Materials systems currently of interest in themanufacture of high-brightness light emitting devices capable ofoperation across the visible spectrum include Group III-Vsemiconductors, particularly binary, ternary, and quaternary alloys ofgallium, aluminum, indium, and nitrogen, also referred to as III-nitridematerials. Typically, III-nitride light emitting devices are fabricatedby epitaxially growing a stack of semiconductor layers of differentcompositions and dopant concentrations on a sapphire, silicon carbide,III-nitride, composite, or other suitable substrate by metal-organicchemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), orother epitaxial techniques. The stack often includes one or more n-typelayers doped with, for example, Si, formed over the substrate, one ormore light emitting layers in an active region formed over the n-typelayer or layers, and one or more p-type layers doped with, for example,Mg, formed over the active region. Electrical contacts are formed on then- and p-type regions.

III-nitride devices are often formed as inverted or flip chip devices,where both the n- and p-contacts formed on the same side of thesemiconductor structure, and most of the light is extracted from theside of the semiconductor structure opposite the contacts.

SUMMARY

A first pixel with a first pixel sidewall is disclosed. A second pixelwith a second pixel sidewall facing the first pixel sidewall is alsodisclosed. A first dynamic optical isolation material between the firstpixel sidewall and the second pixel sidewall and configured to change anoptical state based on a state trigger such that a light behavior at thefirst pixel sidewall for a light emitted by one of the first pixel andthe second pixel is determined by the optical state, is also disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the following description,given by way of example in conjunction with the accompanying drawingswherein:

FIG. 1A is a top view illustration of a micro LED array with an explodedportion;

FIG. 1B is a cross sectional illustration of a pixel matrix withtrenches;

FIG. 1C is a perspective illustration of another pixel matrix withtrenches;

FIG. 1D is a method to affect light at the sidewalls of a pixel;

FIG. 1E is a top view diagram of a pixel array with dynamic opticalisolation material in a opaque state;

FIG. 1F is a top view diagram of a pixel array with dynamic opticalisolation material in a transparent state;

FIG. 1G is a top view diagram of a pixel array with portions of thearray in an active state and other portions of the array in an inactivestate;

FIG. 1H is a cross-section view of a pixel with two dynamic opticalisolation material layers;

FIG. 1I is a cross-section view diagram of a pixel array;

FIG. 2A is a top view of the electronics board with LED array attachedto the substrate at the LED device attach region in one embodiment;

FIG. 2B is a diagram of one embodiment of a two channel integrated LEDlighting system with electronic components mounted on two surfaces of acircuit board;

FIG. 2C is an example vehicle headlamp system; and

FIG. 3 shows an example illumination system.

DETAILED DESCRIPTION

Examples of different light illumination systems and/or light emittingdiode (“LED”) implementations will be described more fully hereinafterwith reference to the accompanying drawings. These examples are notmutually exclusive, and features found in one example may be combinedwith features found in one or more other examples to achieve additionalimplementations. Accordingly, it will be understood that the examplesshown in the accompanying drawings are provided for illustrativepurposes only and they are not intended to limit the disclosure in anyway. Like numbers refer to like elements throughout.

It will be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, these elementsshould not be limited by these terms. These terms may be used todistinguish one element from another. For example, a first element maybe termed a second element and a second element may be termed a firstelement without departing from the scope of the present invention. Asused herein, the term “and/or” may include any and all combinations ofone or more of the associated listed items.

It will be understood that when an element such as a layer, region, orsubstrate is referred to as being “on” or extending “onto” anotherelement, it may be directly on or extend directly onto the other elementor intervening elements may also be present. In contrast, when anelement is referred to as being “directly on” or extending “directlyonto” another element, there may be no intervening elements present. Itwill also be understood that when an element is referred to as being“connected” or “coupled” to another element, it may be directlyconnected or coupled to the other element and/or connected or coupled tothe other element via one or more intervening elements. In contrast,when an element is referred to as being “directly connected” or“directly coupled” to another element, there are no intervening elementspresent between the element and the other element. It will be understoodthat these terms are intended to encompass different orientations of theelement in addition to any orientation depicted in the figures.

Relative terms such as “below,” “above,” “upper,”, “lower,” “horizontal”or “vertical” may be used herein to describe a relationship of oneelement, layer, or region to another element, layer, or region asillustrated in the figures. It will be understood that these terms areintended to encompass different orientations of the device in additionto the orientation depicted in the figures.

Semiconductor light emitting devices (LEDs) or optical power emittingdevices, such as devices that emit ultraviolet (UV) or infrared (IR)optical power, are among the most efficient light sources currentlyavailable. These devices (hereinafter “LEDs”), may include lightemitting diodes, resonant cavity light emitting diodes, vertical cavitylaser diodes, edge emitting lasers, or the like. Due to their compactsize and lower power requirements, for example, LEDs may be attractivecandidates for many different applications. For example, they may beused as light sources (e.g., flash lights and camera flashes) forhand-held battery-powered devices, such as cameras and cell phones. Theymay also be used, for example, for automotive lighting, heads up display(HUD) lighting, horticultural lighting, street lighting, torch forvideo, general illumination (e.g., home, shop, office and studiolighting, theater/stage lighting and architectural lighting), augmentedreality (AR) lighting, virtual reality (VR) lighting, as back lights fordisplays, and IR spectroscopy. A single LED may provide light that isless bright than an incandescent light source, and, therefore,multi-junction devices or arrays of LEDs (such as monolithic LED arrays,micro LED arrays, etc.) may be used for applications where morebrightness is desired or required.

According to embodiments of the disclosed subject matter, LED arrays(e.g., micro LED arrays) may include an array of pixels as shown inFIGS. 1A, 1B, and/or 1C. LED arrays may be used for any applicationssuch as those requiring precision control of LED array segments. Pixelsin an LED array may be individually addressable, may be addressable ingroups/subsets, or may not be addressable. In FIG. 1A, a top view of aLED array 110 with pixels 111 is shown. An exploded view of a 3×3portion of the LED array 110 is also shown in FIG. 1A. As shown in the3×3 portion exploded view, LED array 110 may include pixels 111 with awidth w₁ of approximately 100 μm or less (e.g., 40 μm). The lanes 113between the pixels may be separated by a width, w₂, of approximately 20μm or less (e.g., 5 μm). The lanes 113 may provide an air gap betweenpixels or may contain other material, as shown in FIGS. 1B and 1C andfurther disclosed herein. The distance d₁ from the center of one pixel111 to the center of an adjacent pixel 111 may be approximately 120 μmor less (e.g., 45 μm). It will be understood that the widths anddistances provided herein are examples only, and that actual widthsand/or dimensions may vary.

It will be understood that although rectangular pixels arranged in asymmetric matrix are shown in FIGS. 1A, B and C, pixels of any shape andarrangement may be applied to the embodiments disclosed herein. Forexample, LED array 110 of FIG. 1A may include, over 10,000 pixels in anyapplicable arrangement such as a 100×100 matrix, a 200×50 matrix, asymmetric matrix, a non-symmetric matrix, or the like. It will also beunderstood that multiple sets of pixels, matrixes, and/or boards may bearranged in any applicable format to implement the embodiments disclosedherein.

FIG. 1B shows a cross section view of an example LED array 1000. Asshown, the pixels 1010, 1020, and 1030 correspond to three differentpixels within an LED array such that a separation sections 1041 and/orn-type contacts 1040 separate the pixels from each other. According toan embodiment, the space between pixels may be occupied by an air gap.As shown, pixel 1010 includes an epitaxial layer 1011 which may be grownon any applicable substrate such as, for example, a sapphire substrate,which may be removed from the epitaxial layer 1011. A surface of thegrowth layer distal from contact 1015 may be substantially planar or maybe patterned. A p-type region 1012 may be located in proximity to ap-contact 1017. An active region 1021 may be disposed adjacent to then-type region and a p-type region 1012. Alternatively, the active region1021 may be between a semiconductor layer or n-type region and p-typeregion 1012 and may receive a current such that the active region 1021emits light beams. The p-contact 1017 may be in contact with SiO2 layers1013 and 1014 as well as plated metal layer 1016 (e.g., plated copper).The n type contacts 1040 may include an applicable metal such as Cu. Themetal layer 1016 may be in contact with a contact 1015 which mayreflective.

Notably, as shown in FIG. 1B, the n-type contact 1040 may be depositedinto trenches 1130 created between pixels 1010, 1020, and 1030 and mayextend beyond the epitaxial layer. Separation sections 1041 may separateall (as shown) or part of a wavelength converting layer 1050. It will beunderstood that a LED array may be implemented without such separationsections 1041 or the separation sections 1041 may correspond to an airgap. The separation sections 1041 may be an extension of the n-typecontacts 1040, such that, separation sections 1041 are formed from thesame material as the n-type contacts 1040 (e.g., copper). Alternatively,the separation sections 1041 may be formed from a material differentthan the n-type contacts 1040. According to an embodiment, separationsections 1041 may include reflective material. The material inseparation sections 1041 and/or the n-type contact 1040 may be depositedin any applicable manner such as, for example, but applying a meshstructure which includes or allows the deposition of the n-type contact1040 and/or separation sections 1041. Wavelength converting layer 1050may have features/properties similar to wavelength converting layer 205of FIG. 2A. As noted herein, one or more additional layers may coat theseparation sections 1041. Such a layer may be a first optical materialwhich may be a reflective layer, a scattering layer, an absorptivelayer, or any other applicable layer. One or more passivation layers1019 may fully or partially separate the n-contact 1040 from theepitaxial layer 1011.

The epitaxial layer 1011 may be formed from any applicable material toemit photons when excited including sapphire, SiC, GaN, Silicone and maymore specifically be formed from a III-V semiconductors including, butnot limited to, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP,InAs, InSb, II-VI semiconductors including, but not limited to, ZnS,ZnSe, CdSe, CdTe, group IV semiconductors including, but not limited toGe, Si, SiC, and mixtures or alloys thereof. These examplesemiconductors may have indices of refraction ranging from about 2.4 toabout 4.1 at the typical emission wavelengths of LEDs in which they arepresent. For example, III-Nitride semiconductors, such as GaN, may haverefractive indices of about 2.4 at 500 nm, and III-Phosphidesemiconductors, such as InGaP, may have refractive indices of about 3.7at 600 nm. Contacts coupled to the LED device 200 may be formed from asolder, such as AuSn, AuGa, AuSi or SAC solders.

The n-type region may be grown on a growth substrate and may include oneor more layers of semiconductor material that include differentcompositions and dopant concentrations including, for example,preparation layers, such as buffer or nucleation layers, and/or layersdesigned to facilitate removal of the growth substrate. These layers maybe n-type or not intentionally doped, or may even be p-type devicelayers. The layers may be designed for particular optical, material, orelectrical properties desirable for the light emitting region toefficiently emit light. Similarly, the p-type region 1012 may includemultiple layers of different composition, thickness, and dopantconcentrations, including layers that are not intentionally doped, orn-type layers. An electrical current may be caused to flow through thep-n junction (e.g., via contacts) and the pixels may generate light of afirst wavelength determined at least in part by the bandgap energy ofthe materials. A pixel may directly emit light (e.g., regular or directemission LED) or may emit light into a wavelength converting layer 1050(e.g., phosphor converted LED, “PCLED”, etc.) that acts to furthermodify wavelength of the emitted light to output a light of a secondwavelength.

Although FIG. 1B shows an example LED array 1000 with pixels 1010, 1020,and 1030 in an example arrangement, it will be understood that pixels inan LED array may be provided in any one of a number of arrangements. Forexample, the pixels may be in a flip chip structure, a verticalinjection thin film (VTF) structure, a multi-junction structure, a thinfilm flip chip (TFFC), lateral devices, etc. For example, a lateral LEDpixel may be similar to a flip chip LED pixel but may not be flippedupside down for direct connection of the electrodes to a substrate orpackage. A TFFC may also be similar to a flip chip LED pixel but mayhave the growth substrate removed (leaving the thin film semiconductorlayers un-supported). In contrast, the growth substrate or othersubstrate may be included as part of a flip chip LED.

The wavelength converting layer 1050 may be in the path of light emittedby active region 1021, such that the light emitted by active region 1021may traverse through one or more intermediate layers (e.g., a photoniclayer). According to embodiments, wavelength converting layer 1050 ormay not be present in LED array 1000. The wavelength converting layer1050 may include any luminescent material, such as, for example,phosphor particles in a transparent or translucent binder or matrix, ora ceramic phosphor element, which absorbs light of one wavelength andemits light of a different wavelength. The thickness of a wavelengthconverting layer 1050 may be determined based on the material used orapplication/wavelength for which the LED array 1000 or individual pixels1010, 1020, and 1030 is/are arranged. For example, a wavelengthconverting layer 1050 may be approximately 20 μm, 50 μm or 200 μm. Thewavelength converting layer 1050 may be provided on each individualpixel, as shown, or may be placed over an entire LED array 1000.

Primary optic 1022 may be on or over one or more pixels 1010, 1020,and/or 1030 and may allow light to pass from the active region 101and/or the wavelength converting layer 1050 through the primary optic.Light via the primary optic may generally be emitted based on aLambertian distribution pattern such that the luminous intensity of thelight emitted via the primary optic 1022, when observed from an idealdiffuse radiator, is directly proportional to the cosine of the anglebetween the direction of the incident light and the surface normal. Itwill be understood that one or more properties of the primary optic 1022may be modified to produce a light distribution pattern that isdifferent than the Lambertian distribution pattern.

Secondary optics 1060 which include one or both of the lens 1064 andwaveguide 1062 may be provided with pixels 1010, 1020, and/or 1030. Itwill be understood that although secondary optics are discussed inaccordance with the example shown in FIG. 1B with multiple pixels,secondary optics may be provided for single pixels. Secondary optics maybe used to spread the incoming light (diverging optics), or to gatherincoming light into a collimated beam (collimating optics). Thewaveguide 1062 may be coated with a dielectric material, a metallizationlayer, or the like and may be provided to reflect or redirect incidentlight. In alternative embodiments, a lighting system may not include oneor more of the following: the wavelength converting layer 1050, theprimary optics 1022, the waveguide 1062 and the lens 1065.

Lens 1064 may be formed form any applicable transparent material suchas, but not limited to SiC, aluminum oxide, diamond, or the like or acombination thereof. Lens 1064 may be used to modify a beam of light tobe input into the lens 1064 such that an output beam from the lens 1065will efficiently meet a desired photometric specification. Additionally,lens 1064 may serve one or more aesthetic purpose, such as bydetermining a lit and/or unlit appearance of the multiple LED devices200B.

FIG. 1C shows a cross section of a three dimensional view of a LED array1100. As shown, pixels in the LED array 1100 may be separated bytrenches which are filled to form n-contacts 1140. The pixels may begrown on a substrate 1114 and may include a p-contact 1113, a p-GaNsemiconductor layer 1112, an active region 1111, and an n-Gansemiconductor layer 1110. It will be understood that this structure isprovided as an example only and one or more semiconductor or otherapplicable layers may be added, removed, or partially added or removedto implement the disclosure provided herein. A wavelength convertinglayer 1117 may be deposited on the semiconductor layer 1110 (or otherapplicable layer).

Passivation layers 1115 may be formed within the trenches 1130 andn-contacts 1140 (e.g., copper contacts) may be deposited within thetrenches 1130, as shown. The passivation layers 1115 may separate atleast a portion of the n-contacts 1140 from one or more layers of thesemiconductor. According to an implementation, the n-contacts 1140, orother applicable material, within the trenches may extend into thewavelength converting layer 1117 such that the n-contacts 1140, or otherapplicable material, provide complete or partial optical isolationbetween the pixels.

FIG. 1D shows a method 1200 for generating pixels in a pixel array,according to the subject matter disclosed herein. The pixels in such apixel array may be sub-300 micron large and sidewall material depositiontechniques specific to pixels in the sub-300 micron range may be used todeposit dynamic optical isolation material. As shown at step 1210, adynamic optical isolation material may be attached to pixel sidewalls ofpixels in a pixel array. It will be understood that although the termattached is used, attached may apply as being formed on, grown on,connected to, in contact with, or the like. At step 1220, a statetrigger may be received at the dynamic optical isolation material. Thestate trigger may be a signal or a change in property such as, but notlimited to, a temperature change. The state trigger may be provided byan electronic component such as a microprocessor or a controller, apixel in a pixel array or may be generated by other pixels in the pixelarray. At step 1230, an optical state of the dynamic optical isolationmaterial may be changed based on the received state trigger. The changein optical state may configure the dynamic optical isolation material tointeract with light in a manner that is different than the manner thedynamic optical isolation material interacts with light prior to thechange in the optical state. At step 1240, an emitted light may bereceived at the dynamic optical isolation material and the dynamicoptical isolation material may affect the light based on its opticalstate at step 1250. The emitted light may be generated by the pixel ontowhich the dynamic optical isolation material is attached to or may begenerated by a different pixel.

The efficiency of pixel arrays may increase as a result of the dynamicoptical isolation material disclosed herein. Cross talk may be reducedor eliminated as the dynamic optical isolation material may prevent thelight from a given pixel to emit via its sidewalls into the lanesbetween pixels as well as an adjacent or proximate pixel that is turnedoff, mitigating or preventing an unintended cross lighting effect.Additionally, the dynamic optical isolation material may improve thecontrast of a pixel array that emits segmented light such that there maybe more clearly defined borders between two or more pixels adjacent orproximate to each other.

Alternatively, the efficiency of a pixel array may improve as a resultof reduced or eliminated isolation between pixels, such as whenneighboring pixels are powered on. The dynamic optical isolationmaterial may be configured to allow light to pass through sidewalls suchthat a pixel array or a segment of a pixel array emits a more uniformlight by, for example, emitting light into the lanes between pixels andinto adjacent and proximate pixels to provide a uniform or gradientbased change in light.

According to step 1210 of FIG. 1D, as also shown in FIG. 1E, the dynamicoptical isolation material 1320 may be attached to the sidewalls of thepixels 1315 in a pixel array 1300. As shown in FIG. 1 a and FIG. 1 b ,the pixels may be sub-300 micron wide and may be, for example, 100microns wide or 80 microns wide. The dynamic optical isolation material1320 may occupy all or part of the space in the lanes created betweenthe pixels, and the lanes may be, for example, 20 microns wide. Thedynamic optical isolation material 1320 may be attached to the sidewallsof the pixels 1315 using any applicable technique includingscreen-printing, contact printing, drip coating, spray coating,lithography, or the like.

The dynamic optical isolation material 1320 may be thermochromicmaterial, thermotropic material, electrochromic material or photochromicmaterial.

Thermochromic material may change optical properties as a result oftemperature changes, and may specifically change from a non-transparentstate to a transparent state as a result of temperature change. Thechanges in optical properties for thermochromic material may bereversible. For example, a thermochromic material may change from anoptical state A to an optical state B when the material's temperatureincreases above a temperature X. When the temperature cools to below thetemperature X, or a different threshold temperature Y, the thermochromicmaterial may change back to the optical state A. Optical properties thatmay change in a thermochromic material include the change in color andthe respective opacity/transparency. Thermochromic material may includeleuco dyes such that the leuco dyes are provided in a structural epoxy,a structural polymer or a homogeneous structural material to form thedynamic optical isolation material 1320.

Thermochromic material may change their optical state at a thresholdtemperature. Thermochromic material may include dye absorbing materialssuch that light that reaches the thermochromic material collides withsaid absorbing materials and is partially or fully prevented from beingemitted past the thermochromic material as a result. For example, lightmay collide with absorbing materials and absorb photons, therebycontaining a color at the thermochromic material instead of partially orfully emitting past the thermochromic material. Accordingly, thethermochromic material exhibits an opaque state, as light may not passthrough the material. The thermochromic dyes may be encapsulated with awax and developer in capsules that are the shell of a structuralpolymer. When the wax is in a solid state, the developer and dye may beassociated and the thermochromic material may be colored. The wax may beconfigured to melt at a threshold temperature and the absorbing materialmay be configured to dissolve into the melted binder wax. The dissolvingof the absorbing material results in a change in an optical state aslight that reaches the thermochromic material does not interact with theabsorbing material. As a result, the light may pass through thethermochromic material causing the thermochromic material to have atransparent state.

Thermotropic material may change optical properties as a result oftemperature changes and may specifically change light scatteringproperties as a result of temperature change. The changes in opticalproperties for thermotropic material may be reversible. Thermotropicmaterials may include metal oxide beads in silicon or other organicpolymer, porous metal oxide beads in silicone or other organic polymer,phase change materials in silicon or polymer matrix, liquid crystalcapsules in a silicone or polymer matrix, or the like. Thermotropicmaterial may be configured to provide light scattering modulationestablished based on changes in refractive index. As an example,thermotropic material may include a crystalline paraffin wax, whichexhibits high scattering properties when the wax is solid. The wax maybe configured to melt at the threshold temperature, resulting in a lowscattering or non-scattering state as the melted wax may exhibit low orno scattering properties.

The light scattering modulation in thermotropic materials may beestablished based on changes in refractive index differences as afunction of temperature, for example, in mixtures of organic polymersand metal oxides such as silicone with a high dn/dt. Alternatively,temperature sensitive liquid crystalline materials may transition to anisotropic phase at threshold temperatures. Alternatively or in addition,the thermotropic material may include porous silica material, whichincludes a large number of interfaces as a result of its porousstructure. The pores may be filled with, for example, silicone and thethermotropic material containing the porous silica may change from ascattering state to a low scattering or non-scattering state as thetemperature of the material reaches a threshold temperature. Thescattering may reduce due to the refractive index of the siliconedecreasing at the threshold temperature such that the refractive indexdifference between the silicone and the silica becomes smaller, thusleading to less scattering at or past the threshold temperature. Theporous silica may have 50-1400 nm open porosity.

In an alternative configuration the thermotropic material may includesalts that are configured to change scattering properties based on thehydration and dehydration properties of the salts such that a highertemperature may cause the salts to dehydrate, resulting in a higherscattering.

Electrochromic material may change optical properties as a result ofcharge applied to the electrochromic material to cause electrochemicalredox reactions. The changes in optical properties for electrochromicmaterial may be reversible. Electrochromic material may includetransition metal oxides including tungsten oxide, NiO materials,polyaniline, viologens, polyoxotungstates, and the like. Electrochromicmaterial may change optical properties including changing to atransparent state, an opaque state, or a reflective state as a result ofan electric charge being applied to the material. As an example, when avoltage is applied to electrodes in connection with the electrochromicmaterial, ions may migrate from one electrode location to a differentelectrode location. The migration may cause the particles in theElectrochromic material to change from a transparent state to areflective state. Alternatively or in addition, the electrochromicmaterial may contain a die that changes states when a current passesthrough the die.

Photochromic material may change optical properties as a result ofchanges in light intensity applied to the photochromic material.Specifically, photochromic material may change from a non-transparentstate to a transparent state as a result of changes in light applied tothe material. The changes in optical properties for photochromicmaterial may be reversible. For example, a photochromic material maychange from an optical state A to an optical state B when ultravioletlight is emitted onto the material. When the ultraviolet light isremoved, the photochromic material may change back to exhibiting theoptical state A. As a specific example, photochromic material mayexhibit a non-transparent state when no light is incident on thematerial. When a pixel is activated such that the pixel emits a bluelight, the blue light may reach the photochromic material and thephotochromic material may change its optical state to a transparentstate such that the light from the pixel emits through the material.

Dynamic optical isolation material 1320 may be attached to pixelsidewalls such that it is attached to all or part of the light-emittingcomponent of the pixel and all or part of the wavelength convertinglayer of the pixel. An example pixel array is shown in FIG. 1I anddescribed in more detail herein.

At step 1220 of FIG. 1D, as also shown in FIGS. 1E and 3 b, a statetrigger may be received at the dynamic optical isolation material 1320.A state trigger may be a condition, a property change, a signal, or thelike, and may be received in the form of an optical addressing, anelectrical addressing, a temperature change, or the like. An opticaladdressing may be a light based trigger such as emitting a UV light ontothe dynamic optical isolation material. An electrical addressing may bebased on a voltage or current applied to a dynamic optical isolationmaterial. A temperature change may be caused by a heating or coolingcomponent or by the heat generated by pixel array components includingadjacent or proximate pixels when they are switched on.

A state trigger may be dynamic optical isolation material dependent suchthat a state trigger for a first material may not be a state trigger fora second material. As an example, a temperature increase to a thresholdtemperature X may be a state trigger for a thermochromic dynamic opticalisolation material but may not be a state trigger for an electrochromicdynamic optical isolation material. Alternatively, as an example,applying a charge may be a state trigger for an electrochromic dynamicoptical isolation material but applying the same charge may not be astate trigger for a thermochromic dynamic optical isolation material.

A state trigger may be provided explicitly or may be providedimplicitly. An explicitly provided state trigger may be initiated by apixel or external microcontroller, a sensor, or any component configuredto provide an explicit state trigger. As an example, a microcontrollermay be configured to initiate a charge that is applied to anelectrochromic dynamic optical isolation material. The microcontrollermay initiate the charge based on a signal or determination to change theoptical state of a dynamic optical isolation material. As anotherexample, a UV light emitter may emit UV light at a photochromic materialbased on a signal or determination to change the optical state of adynamic optical isolation material.

An implicitly provided state trigger may be initiated as a result of achange in a condition. As an example, a first row of pixels in a pixelarray may change from an inactive mode to an active mode. The pixels inthe active mode may generate heat as byproduct of emitting light. Theheat may result in a temperature increase beyond a temperature X,providing a state trigger to the thermotropic dynamic optical isolationmaterial attached to a second row of pixels adjacent to the first row ofpixels. A plurality of pixels may be required to generate a thresholdamount of heat to increase the temperature beyond a thresholdtemperature X, to provide a state trigger for an adjacent pixel tochange an optical state.

An implicit state trigger for dynamic isolation material attached to apixel may be provided by the pixel itself. As an example, the heatgenerated by the given pixel, when activated, may provide an implicitstate trigger as the heat may cause the temperature at the dynamicisolation optical isolation material to rise above a state triggergenerating threshold temperature X. As an example, the temperature X maybe between 40° C. and 150° C.

An implicit state trigger for dynamic isolation material attached to apixel may be provided by a combination of the pixel itself and one ormore adjacent or proximate pixels. As an example, the heat generated bythe given pixel alone, when activated, may not be sufficient to raisethe temperature at its dynamic isolation material above a thresholdtemperature X. However, the combination of the heat generated by theactivated pixel and the heat generated by an adjacent pixel may causethe temperature at the dynamic optical isolation material to rise abovea state trigger generating threshold temperature X. Additionally, if thedynamic optical isolation materials of adjacent or proximate pixels havethe same properties, then the dynamic optical isolation materials ofsuch pixels may each change an optical state based on the same statetrigger.

At step 1230 of FIG. 1D, an optical state of dynamic optical isolationmaterial may be changed based on a received state trigger. The change inoptical state may result in a dynamic optical isolation material toswitch between one or more states such as a transparent state, anon-transparent or absorbing state, a scattering state, a non-scatteringstate, or a reflective state. It will be understood that a change inoptical state may be a substantial change from a first state to a secondstate but need not be an all-or-nothing binary on/off designation. Forexample, a dynamic optical isolation material may change from an opaquestate to a transparent state such that the material is 95% transparent.Notably, although the dynamic optical isolation material may stillprevent 5% of light from being emitted, it will be understood that thematerial is substantially transparent. It will also be understood thatalthough a 95%/5% non-limiting example is used herein, the percentagesor criteria for a change in state may depend on the type of dynamicoptical isolation material, the optical states, the application of thepixel array, or the like.

FIG. 1E shows the pixel array 1300 with pixels 1315 having sidewallswith dynamic optical isolation material 1320. The dynamic opticalisolation material 1320 in FIG. 1E may be in an opaque state asrepresented by the dark dynamic optical isolation material 1320. A statetrigger may be received at the dynamic optical isolation material andthe state trigger may be, for example, the dynamic optical isolationmaterial being heated to a threshold temperature X. The state triggermay be an explicit temperature increase to a threshold temperature X atthe dynamic optical isolation material 1320 and caused by a heatingmechanism. Alternatively, a state trigger may be an implicit triggersuch that the pixels 1315 may be activated and the heat dissipated bythe pixels may cause the temperature at the optical isolation material1320 to reach the threshold temperature X.

FIG. 1F shows the pixel array with the dynamic optical isolationmaterial 1320 in a transparent state, as represented by the lightdynamic optical isolation material 1320. The change from the opaquestate in FIG. 1E to the transparent state in FIG. 1F may be a result ofthe implicit or explicit state trigger of the dynamic optical isolationmaterial 1320 temperature reaching above a threshold temperature X.

FIG. 1G shows a pixel array 1400 that contains a plurality of pixelsarranged in a matrix. It will be understood that although a matrix pixelarrangement is shown, this disclosure may be applied to any pixel arrayconfigured to include pixels adjacent or proximate to each other. Thepixel array 1400 may be segmented such that different segments of thearray may be operated independently of each other. As an example, asshown in FIG. 1G, the pixel array 1400 may be contain three segments1410, 1420 and 1430 that are operated independently. It will beunderstood that although specific segments are shown in this example,the segment arrangement may be dynamic such that specific segments maybe utilized for a given application and the same pixel array may besegmented in a different manner with different pixels per segment, for adifferent application.

As an example, pixel array 1400 may correspond to a front facingautomotive lighting system. The dynamic optical isolation material 1415,1425, and 1435 may contain thermochromic material. The pixel array mayreceive input from an automotive sensor configured to detect thelocation of oncoming traffic and may activate pixels such that lightemitted from the pixel array illuminates the scene for a driver withoutemitting light at or towards the oncoming traffic. Based on the inputfrom the automotive sensor, pixels in segments 1410 and 1420 may beactivated and pixel in segment 1430 may be inactive. The dynamic opticalisolation material 1415, 1425, and 1435 may be a thermochromic materialconfigured to change from an opaque state below a threshold temperatureX to a transparent state at or above threshold temperature X. The activepixels in segments 1410 and 1420 may generate heat such that thetemperature at the dynamic optical isolation material 1415 and 1425increases to the threshold temperature X. The temperature at the dynamicoptical isolation material 1435 adjacent to the inactive pixels insegment 1430 may remain below the threshold temperature X. As a result,as shown in FIG. 1G, the dynamic optical isolation material 1415 and1425 may change from an opaque optical state to a transparent opticalstate. The dynamic optical isolation material 1435 may remain in anopaque optical state. This configuration may allow a more uniform lightto be emitted by segments 1410 and 1420 as light from an emitter maypass through the sidewalls of the active pixels towards adjacent orproximate pixels. This configuration may also provide a sharp contrastat the edges of the segments 1410 and 1420 such that there is no crosstalk between the active pixels of segments 1410 and 1420 and theinactive pixels of segment 1430.

As another example, pixel array 1400 may correspond to a street lightpanel. The dynamic optical isolation material 1415, 1425, and 1435 mayinclude photochromic material. Further, the dynamic optical isolationmaterial 1415, 1425, and 1435 may be a photochromic material configuredto change from an opaque state when no UV light is emitted onto it to atransparent state when UV light is emitted onto it. The pixel array mayreceive input from a controller regarding which pixel segments are to beilluminated based on foot traffic patterns on a corresponding street.Based on the input from the controller, a UV light emitter may emit UVlight at the pixels in segments 1410 and 1420 such that the UV light isnot emitted at pixels in segment 1430. As a result, as shown in FIG. 1G,the dynamic optical isolation material 1415 and 1425 may change from anopaque optical state to a transparent optical state. The dynamic opticalisolation material 1435 may remain in an opaque optical state. Thisconfiguration may allow a more uniform light to be emitted by segments1410 and 1420 as light from an emitter may pass through the sidewalls ofthe active pixels towards adjacent or proximate pixels. Thisconfiguration may also provide a sharp contrast at the edges of thesegments 1410 and 1420 such that there is no cross talk between theactive pixels of segments 1410 and 1420 and the inactive pixels ofsegment 1430.

As shown in FIG. 1H, multiple dynamic optical isolation materials 1521and 1522 may be attached to the sidewalls of a pixel 1510. The multipledynamic optical isolation materials 1521 and 1522 may be different typesof material such as, for example, a thermotropic material and athermochromic material. Alternatively, the multiple dynamic opticalisolation materials 1521 and 1522 may be the same type of material withdifferent optical properties. As an example, the materials 1521 and 1522may both be thermochromic such that the material 1521 may change anoptical state at a lower threshold temperature than the material 1522.Multiple dynamic optical isolation materials may allow for more preciselight control when compared to a single material. As an example,material 1521 may be thermochromic and material 1522 may bethermotropic. A temperature X may be a state trigger for both materials1521 and 1522 such that the thermochromic material 1521 may change to atransparent state and thermotropic material 1522 may change to anon-scattering state. The transparent and non-scattering states mayallow for light emitted by the pixel 1510 to exit through the sidewallsand towards other adjacent or proximate pixels. A reduction in thetemperature below temperature X may initiate a second state trigger forboth materials 1521 and 1522 such that thermochromic material 1521 mayenter an opaque state and thermotropic material 1522 may enter areflective state. The opaque state of the thermochromic material 1521may prevent light emitted by the pixel 1510 from exiting the pixel viathe sidewalls. The reflective state of the thermotropic material 1522may cause light emitted by an adjacent pixel to reflect away from thepixel 1510 when the light reaches the material 1522. The combinedresulting effect of the two dynamic optical isolation materials may bethat external light is emitted away from the sidewalls of pixel 1510 andinternal light does not exit the pixel 1510 via its sidewalls.

According to an embodiment, multiple dynamic optical isolation materials1530 and 1531 may be attached to the non-sidewall surface (e.g., topsurface, bottom surface, etc.) of a pixel 1510. The multiple dynamicoptical isolation materials 1530 and 1531 may be a single layer ormaterial or may be different material, as shown. The multiple dynamicoptical isolation material 1530 and 1531 may be deposited at the sametime as or at a different time than materials 1521 and 1522. Themultiple dynamic optical isolation materials 1530 and 1531 may bedifferent types of material such as, for example, a thermotropicmaterial and a thermochromic material. Alternatively, the multipledynamic optical isolation materials 1530 and 1531 may be the same typeof material with different optical properties. As an example, thedynamic optical isolation materials 1530 and 1531 may both bethermochromic such that the dynamic optical isolation material 1531 maychange an optical state at a lower threshold temperature than thematerial 1530, or vice versa. Multiple dynamic optical isolationmaterials 1530 and 1531 may allow for reduction in cross talk and/or maybe used to alternate between an on-state and off state of the pixel1510.

FIG. 1I shows an example pixel array 600 including pixels 1675manufactured in accordance with the techniques disclosed herein andincluding light-emitting devices 1670 that include a GaN layer 1650,active region 1690, solder 1680, and pattern sapphire substrate (PSS)pattern 1660. The wavelength converting layers 1620 may be mounted ontothe light emitting devices 1670, as shown.

A wavelength converting layer may contain material configured to convertone or more properties of light. The wavelength converting layer mayconvert a property of light, such as, but not limited to, itswavelength, its phase, or the like. A wavelength converting layer mayconvert a property of light based on a collision of one or moreparticles in a wavelength converting layer with an incoming light,followed by a photon release.

A wavelength converting layer may contain applicable luminescent oroptically scattering material such as phosphor particles with or withoutactivation from rare earth ions, phosphor in glass (PiG), phosphor insilicon, ceramic phosphor, zinc barium borate, Ce(III) doped garnetmaterials such as (Y,Gd)₃(AlGa)₅O₁₂:Ce, aluminum nitride, aluminumoxynitride (AlON), barium sulfate, barium titanate, calcium titanate,cubic zirconia, diamond, gadolinium gallium garnet (GGG), lead lanthanumzirconate titanate (PLZT), lead zirconate titanate (PZT), sapphire,silicon aluminum oxynitride (SiAlON), silicon carbide, siliconoxynitride (SiON), strontium titanate, titanium oxide, yttrium aluminumgarnet (YAG), zinc selenide, zinc sulfide, and zinc telluride, diamond,silicon carbide (SiC), single crystal aluminum nitride (AlN), galliumnitride (GaN), or aluminum gallium nitride (AlGaN) or any transparent,translucent, or scattering ceramic, optical glass, high index glass,sapphire, alumina, III-V semiconductors such as gallium phosphide, II-VIsemiconductors such as zinc sulfide, zinc selenide, and zinc telluride,group IV semiconductors and compounds, metal oxides, metal fluorides, anoxide of any of the following: aluminum, antimony, arsenic, bismuth,calcium, copper, gallium, germanium, lanthanum, lead, niobium,phosphorus, tellurium, thallium, titanium, tungsten, zinc, or zirconium,polycrystalline aluminum oxide (transparent alumina), aluminumoxynitride (AlON), cubic zirconia (CZ), gadolinium gallium garnet (GGG),gallium phosphide (GaP), lead zirconate titanate (PZT), silicon aluminumoxynitride (SiAlON), silicon carbide (SiC), silicon oxynitride (SiON),strontium titanate, yttrium aluminum garnet (YAG), zinc sulfide (ZnS),spinel, Schott glass LaFN21, LaSFN35, LaF2, LaF3, LaF10, NZK7, NLAF21,LaSFN18, SF59, or LaSF3, Ohara glass SLAM60 or SLAH51, and may comprisenitride luminescent material, garnet luminescent material, orthosilicateluminescent material, SiAlON luminescent material, aluminate luminescentmaterial, oxynitride luminescent material, halogenide luminescentmaterial, oxyhalogenide luminescent material, sulfide luminescentmaterial and/or oxysulfide luminescent material, luminescent quantumdots comprising core materials chosen from cadmium sulfide, cadmiumselenide, zinc sulfide, zinc selenide, and may be chosen formSrLiAl₃N₄:Eu (II) (strontium-lithium-aluminum nitride: europium (II))class, Eu(II) doped nitride phosphors like (Ba,Sr,Ca)2Si5-xAlxOxN8:Eu,(Sr,Ca)SiAlN3:Eu or SrLiAl3N4:Eu, or any combination thereof.

Dynamic optical isolation materials 1630 may be applied to thewavelength converting layers 1620. The wavelength converting layers 1620may be mounted onto a GaN layer 1650 via a pattern sapphire substrate(PSS) pattern 1660. The GaN layer 1650 may be bonded to or grown over anactive region 1690 and the light-emitting device 1670 may be connectedto a solder 780. Dynamic optical isolator material 1640 may also beapplied to the sidewalls of the GaN layer 1650.

As an example, the pixels 1675 of FIG. 1I may correspond to the pixels111 of FIG. 1A. Specifically, as shown in FIG. 1A, the pixels 111 maycorrespond to the pixels 1675 of FIG. 1I after the wavelength convertinglayers 1620 are mounted onto the light emitting devices 1670. When thepixels 111 or 1675 are activated, the respective active regions 1690 ofthe pixels may generate a light. The light may pass through thewavelength converting layer 1620 and may substantially be emitted fromthe surface of the wavelength converting layer 1620. Light that reachesdynamic optical isolation material 1630 and/or 1640 may pass through thedynamic optical isolation material 1630 and/or 1640 if the material isin a transparent state. Alternatively or in addition, the light may bealtered, absorbed, reflected or otherwise modified based on the opticalstate of the dynamic optical isolation material 1630 and/or 1640.

FIG. 2A is a top view of an electronics board with an LED array 410attached to a substrate at the LED device attach region 318 in oneembodiment. The electronics board together with the LED array 410represents an LED system 400A. Additionally, the power module 312receives a voltage input at Vin 497 and control signals from theconnectivity and control module 316 over traces 418B, and provides drivesignals to the LED array 410 over traces 418A. The LED array 410 isturned on and off via the drive signals from the power module 312. Inthe embodiment shown in FIG. 2A, the connectivity and control module 316receives sensor signals from the sensor module 314 over trace 418C.Pixels in the LED array 410 may be created in accordance with the stepsFIG. 1D and as shown in FIGS. 1E-H.

FIG. 2B illustrates one embodiment of a two channel integrated LEDlighting system with electronic components mounted on two surfaces of acircuit board 499. As shown in FIG. 2B, an LED lighting system 400Bincludes a first surface 445A having inputs to receive dimmer signalsand AC power signals and an AC/DC converter circuit 412 mounted on it.The LED system 400B includes a second surface 445B with the dimmerinterface circuit 415, DC-DC converter circuits 440A and 440B, aconnectivity and control module 416 (a wireless module in this example)having a microcontroller 472, and an LED array 410 mounted on it. TheLED array 410 is driven by two independent channels 411A and 411B. Inalternative embodiments, a single channel may be used to provide thedrive signals to an LED array, or any number of multiple channels may beused to provide the drive signals to an LED array.

The LED array 410 may include two groups of LED devices. In an exampleembodiment, the LED devices of group A are electrically coupled to afirst channel 411A and the LED devices of group B are electricallycoupled to a second channel 411B. Each of the two DC-DC converters 440Aand 440B may provide a respective drive current via single channels 411Aand 411B, respectively, for driving a respective group of LEDs A and Bin the LED array 410. The LEDs in one of the groups of LEDs may beconfigured to emit light having a different color point than the LEDs inthe second group of LEDs. Control of the composite color point of lightemitted by the LED array 410 may be tuned within a range by controllingthe current and/or duty cycle applied by the individual DC/DC convertercircuits 440A and 440B via a single channel 411A and 411B, respectively.Although the embodiment shown in FIG. 2B does not include a sensormodule (as described in FIG. 2A), an alternative embodiment may includea sensor module.

The illustrated LED lighting system 400B is an integrated system inwhich the LED array 410 and the circuitry for operating the LED array410 are provided on a single electronics board. Connections betweenmodules on the same surface of the circuit board 499 may be electricallycoupled for exchanging, for example, voltages, currents, and controlsignals between modules, by surface or sub-surface interconnections,such as traces 431, 432, 433, 434 and 435 or metallizations (not shown).Connections between modules on opposite surfaces of the circuit board499 may be electrically coupled by through board interconnections, suchas vias and metallizations (not shown).

According to embodiments, LED systems may be provided where an LED arrayis on a separate electronics board from the driver and controlcircuitry. According to other embodiments, a LED system may have the LEDarray together with some of the electronics on an electronics boardseparate from the driver circuit. For example, an LED system may includea power conversion module and an LED module located on a separateelectronics board than the LED arrays.

According to embodiments, an LED system may include a multi-channel LEDdriver circuit. For example, an LED module may include embedded LEDcalibration and setting data and, for example, three groups of LEDs. Oneof ordinary skill in the art will recognize that any number of groups ofLEDs may be used consistent with one or more applications. IndividualLEDs within each group may be arranged in series or in parallel and thelight having different color points may be provided. For example, warmwhite light may be provided by a first group of LEDs, a cool white lightmay be provided by a second group of LEDs, and a neutral white light maybe provided by a third group.

FIG. 2C shows an example vehicle headlamp system 300 including a vehiclepower 302 including a data bus 304. A sensor module 307 may be connectedto the data bus 304 to provide data related to environment conditions(e.g. ambient light conditions, temperature, time, rain, fog, etc),vehicle condition (parked, in-motion, speed, direction),presence/position of other vehicles, pedestrians, objects, or the like.The sensor module 307 may be similar to or the same as the sensor module314 of FIG. 2A. AC/DC Converter 305 may be connected to the vehiclepower 302. Pixels in the active headlamp 330 may be created inaccordance with the steps FIG. 1D and as shown in FIGS. 1E-H.

The power module 312 (AC/DC converter) of FIG. 2C may be the same as orsimilar to the AC/DC converter 412 of FIG. 2B and may receive AC powerfrom the vehicle power 302. It may convert the AC power to DC power asdescribed in FIG. 2B for AC/DC converter 412. The vehicle head lampsystem 300 may include an active head lamp 330 which receives one ormore inputs provided by or based on the AC/DC converter 305,connectivity and control module 306, and/or sensor module 307. As anexample, the sensor module 307 may detect the presence of a pedestriansuch that the pedestrian is not well lit, which may reduce thelikelihood that a driver sees the pedestrian. Based on such sensorinput, the connectivity and control module 306 may output data to theactive head lamp 330 using power provided from the AC/DC converter 305such that the output data activates a subset of LEDs in an LED arraycontained within active head lamp 330. The subset of LEDs in the LEDarray, when activated, may emit light in the direction where the sensormodule 307 sensed the presence of the pedestrian. These subset of LEDsmay be deactivated or their light beam direction may otherwise bemodified after the sensor module 207 provides updated data confirmingthat the pedestrian is no longer in a path of the vehicle that includesvehicle head lamp system.

FIG. 3 shows an example system 1350 which includes an applicationplatform 1360, LED systems 552 and 556, and optics 554 and 558. Pixelsin the arrays of LED systems 552 and 556 may be created in accordancewith the steps FIG. 1D and as shown in FIGS. 1E-H. The LED System 552produces light beams 561 shown between arrows 561 a and 561 b. The LEDSystem 556 may produce light beams 562 between arrows 562 a and 562 b.In the embodiment shown in FIG. 3 , the light emitted from LED System552 passes through secondary optics 554, and the light emitted from theLED System 556 passes through secondary optics 558. In alternativeembodiments, the light beams 561 and 562 do not pass through anysecondary optics. The secondary optics may be or may include one or morelight guides. The one or more light guides may be edge lit or may havean interior opening that defines an interior edge of the light guide.LED systems 552 and/or 556 may be inserted in the interior openings ofthe one or more light guides such that they inject light into theinterior edge (interior opening light guide) or exterior edge (edge litlight guide) of the one or more light guides. LEDs in LED systems 552and/or 556 may be arranged around the circumference of a base that ispart of the light guide. According to an implementation, the base may bethermally conductive. According to an implementation, the base may becoupled to a heat-dissipating element that is disposed over the lightguide. The heat-dissipating element may be arranged to receive heatgenerated by the LEDs via the thermally conductive base and dissipatethe received heat. The one or more light guides may allow light emittedby LED systems 552 and 556 to be shaped in a desired manner such as, forexample, with a gradient, a chamfered distribution, a narrowdistribution, a wide distribution, an angular distribution, or the like.

In example embodiments, the system 1350 may be a mobile phone of acamera flash system, indoor residential or commercial lighting, outdoorlight such as street lighting, an automobile, a medical device, AR/VRdevices, and robotic devices. The LED System 400A shown in FIG. 2A andvehicle head lamp system 300 shown in FIG. 2C illustrate LED systems 552and 556 in example embodiments.

The application platform 1360 may provide power to the LED systems 552and/or 556 via a power bus via line 565 or other applicable input, asdiscussed herein. Further, application platform 1360 may provide inputsignals via line 565 for the operation of the LED system 552 and LEDsystem 556, which input may be based on a user input/preference, asensed reading, a pre-programmed or autonomously determined output, orthe like. One or more sensors may be internal or external to the housingof the application platform 1360. Alternatively or in addition, as shownin the LED system 400 of FIG. 2A, each LED System 552 and 556 mayinclude its own sensor module, connectivity and control module, powermodule, and/or LED devices.

In embodiments, application platform 1360 sensors and/or LED system 552and/or 556 sensors may collect data such as visual data (e.g., LIDARdata, IR data, data collected via a camera, etc.), audio data, distancebased data, movement data, environmental data, or the like or acombination thereof. The data may be related a physical item or entitysuch as an object, an individual, a vehicle, etc. For example, sensingequipment may collect object proximity data for an ADAS/AV basedapplication, which may prioritize the detection and subsequent actionbased on the detection of a physical item or entity. The data may becollected based on emitting an optical signal by, for example, LEDsystem 552 and/or 556, such as an IR signal and collecting data based onthe emitted optical signal. The data may be collected by a differentcomponent than the component that emits the optical signal for the datacollection. Continuing the example, sensing equipment may be located onan automobile and may emit a beam using a vertical-cavitysurface-emitting laser (VCSEL). The one or more sensors may sense aresponse to the emitted beam or any other applicable input.

In example embodiment, application platform 1360 may represent anautomobile and LED system 552 and LED system 556 may representautomobile headlights. In various embodiments, the system 1350 mayrepresent an automobile with steerable light beams where LEDs may beselectively activated to provide steerable light. For example, an arrayof LEDs may be used to define or project a shape or pattern orilluminate only selected sections of a roadway. In an exampleembodiment, Infrared cameras or detector pixels within LED systems 552and/or 556 may be sensors (e.g., similar to sensors module 314 of FIG.2A and 307 of FIG. 2C) that identify portions of a scene (roadway,pedestrian crossing, etc.) that require illumination.

Having described the embodiments in detail, those skilled in the artwill appreciate that, given the present description, modifications maybe made to the embodiments described herein without departing from thespirit of the inventive concept. Therefore, it is not intended that thescope of the invention be limited to the specific embodimentsillustrated and described. Although features and elements are describedabove in particular combinations, one of ordinary skill in the art willappreciate that each feature or element can be used alone or in anycombination with the other features and elements. In addition, themethods described herein may be implemented in a computer program,software, or firmware incorporated in a computer-readable medium forexecution by a computer or processor. Examples of computer-readablemedia include electronic signals (transmitted over wired or wirelessconnections) and computer-readable storage media. Examples ofcomputer-readable storage media include, but are not limited to, a readonly memory (ROM), a random access memory (RAM), a register, cachememory, semiconductor memory devices, magnetic media such as internalhard disks and removable disks, magneto-optical media, and optical mediasuch as CD-ROM disks, and digital versatile disks (DVDs).

The invention claimed is:
 1. A device comprising: a microLED array comprising a plurality of microLEDs, each microLED separated from an adjacent microLED in the array by a trench, each microLED having sidewalls; and a dynamic optical isolation material attached to a sidewall of a first microLED in the array, the sidewall located in the trench between the first microLED and another microLED in the array, the dynamic optical isolation material switchable between a plurality of optical states comprising a first optical state configured to hinder a transmission of light through the dynamic optical isolation material and a second optical state configured to allow light to pass through the dynamic optical isolation material, the dynamic optical isolation material configured to switch between optical states based on a state trigger, the trench between the first microLED and the another microLED in the array configured so that when the dynamic optical isolation material in the trench is in the second optical state, the trench is substantially transparent.
 2. The device of claim 1, wherein each microLED is individually addressable.
 3. The device of claim 1, wherein the microLED array has a monolithic structure.
 4. The device of claim 1, wherein each microLED has a width of 40 μm or less.
 5. The device of claim 1, wherein each microLED is a pixel element.
 6. The device of claim 1, comprising: a controller configured to send input to the microLED array to illuminate a contiguous subset of the plurality of microLEDs and wherein the dynamic optical isolation material in the trenches between two microLEDs in the contiguous subset is in the second optical state.
 7. An illumination system comprising: an LED array comprising: a plurality of LEDs, each LED separated from an adjacent LED in the array by a trench, each LED having sidewalls; and a dynamic optical isolation material attached to a sidewall of a first LED in the array, the sidewall located in the trench between the first LED and another LED in the array, the dynamic optical isolation material switchable between a plurality of optical states comprising a first optical state configured to hinder a transmission of light through the dynamic optical isolation material and a second optical state configured to allow light to pass through the dynamic optical isolation material, the dynamic optical isolation material configured to switch between optical states based on a state trigger, the trench between the first LED and the another LED in the array configured so that when the dynamic optical isolation material in the trench is in the second optical state, the trench is substantially transparent; and one or more optical elements arranged to form an output illumination beam from light emitted by the LEDs in the LED array.
 8. The illumination system of claim 7, wherein the one or more optical elements comprises a lens.
 9. The illumination system of claim 7, wherein the one or more optical elements comprises a waveguide.
 10. The illumination system of claim 7, wherein each LED in the LED array is individually addressable.
 11. The illumination system of claim 7, wherein each LED in the LED array has a width of 100 μm or less.
 12. The illumination system of claim 7, wherein each LED is a microLED.
 13. The illumination system of claim 7, comprising: a controller configured to send input to the microLED array to illuminate a contiguous subset of the plurality of microLEDs and wherein the dynamic optical isolation material in the trenches between two microLEDs in the contiguous subset is in the second optical state.
 14. A vehicle headlamp comprising the illumination system of claim 7, wherein the one or more optical elements comprises a lens.
 15. A mobile device comprising: a camera; and a flash illumination system comprising: an LED array comprising: a plurality of LEDs, each LED separated from an adjacent LED in the array by a trench, each LED having sidewalls; and a dynamic optical isolation material attached to a sidewall of a first LED in the array, the sidewall located in the trench between the first LED and another LED in the array, the dynamic optical isolation material switchable between a plurality of optical states comprising a first optical state configured to hinder a transmission of light through the dynamic optical isolation material and a second optical state configured to allow light to pass through the dynamic optical isolation material, the dynamic optical isolation material configured to switch between optical states based on a state trigger, the trench between the first LED and the another LED in the array configured so that when the dynamic optical isolation material in the trench is in the second optical state, the trench is substantially transparent; and a lens arranged to form an output flash illumination beam from light emitted by the LED pixels in the LED array.
 16. The mobile device of claim 15, wherein each LED in the LED array is individually addressable.
 17. The mobile device of claim 15, wherein the LED array has a monolithic structure.
 18. The mobile device of claim 15, wherein each LED in the LED array has a width of 100 μm or less.
 19. The mobile device of claim 15, wherein each LED is a microLED.
 20. The mobile device of claim 15, comprising: a controller configured to send input to the microLED array to illuminate a contiguous subset of the plurality of microLEDs and wherein the dynamic optical isolation material in the trenches between two microLEDs in the contiguous subset is in the second optical state. 